1. Field of the Invention
The present invention relates to a tubular needle and a method of manufacturing the needle. For example, the needle according to the present invention can be utilized for communicating inside to outside of a liquid housing body by penetrating an elastic body which blocks an opening of the liquid housing body. For example, the needle according to the present invention can be utilized for penetrating an elastic body which blocks an opening of an ink cartridge.
2. Description of the Related Art
Japanese Patent Application Publication NO.2005-14437 discloses an ink jet printer. This ink jet printer has an ink jet head for discharging ink toward a printing medium, a space for housing an ink cartridge, and a needle which is located at a position facing the space. The needle has a tubular member. The tubular member dwindles toward one end. A through hole is formed on a side wall of the tubular member.
The ink cartridge has an elastic body which blocks an opening. When the ink cartridge is housed in the space, the needle penetrates the elastic body. Ink in the ink cartridge passes through the inside of the needle via the through hole of the needle. The ink which passes through the inside of the needle is sent to the ink jet head.
When the needle penetrates the elastic body, the elastic body expands toward the needle. In this case, the elastic body may reach the inside of the through hole. When the needle moves with respect to the elastic body in the state where the elastic body has reached the inside of the through hole, the elastic body interferes with an inner surface of the through hole. As a result, the elastic body may be peeled off by the inner surface of the through hole.
In FIG. 5 of Japanese Patent Application Publication NO.11-207982, a needle with the following configuration is disclosed. This needle has an outer slanted portion formed on an outer surface of a tubular member along the periphery of a through hole. The outer slanted portion slants down toward the through hole. This document discloses that the outer slanted portion is circular.
In this needle, the outer slanted portion is formed along the periphery of the through hole. In this case, when the needle moves with respect to the elastic body, the outer slanted portion pushes back the elastic body toward a side opposite to the needle. Thus, the elastic body which has reached the inside of the through hole is pushed back in a direction away from the through hole. For this reason, even when the needle moves with respect to the elastic body in the state where the elastic body has reached the inside of the through hole, it may be possible to avoid the elastic body from interfering with the inner surface of the through hole. Therefore, it is possible to make it harder for the elastic body to be peeled of by the inner surface of the through hole.